Whether you want to move out, or get one of your roommates to leave, it's important to understand the legal consequences of one roommate leaving early.

All too frequently, living arrangements that look promising when you’re just friends turn into disasters when you become housemates. Maybe it’s the gym bag dumped on the kitchen table every evening, the inconsiderate parties on work nights, or the “occasional girlfriend” who turns out to be a regular, unpleasant presence. Whether you want to move out, or get one of your roommates to leave, it's important to understand the legal consequences of one roommate leaving early. (This is addition to the legal consequences of all tenants breaking a lease and leaving early).

When cotenants split, there can be serious consequences beyond hurt feelings. The remaining roommates must scramble to cover the departed tenant’s rent share, and the one who has moved on may find herself at the receiving end of a small claims court case demanding her share of rent.

Legal Consequences of a Roommate Leaving Early

In a month-to-month tenancy, a cotenant who wants to leave must give the landlord the required legal notice—30 days in most states. Forget trying to leave on short notice—most landlords won’t prorate a month’s rent. This means that the remaining tenants will have the same amount of time to hustle up a replacement. (Remember, this will require the landlord's approval since your lease or rental agreement undoubtedly has a clause prohibiting unauthorized occupants.) Of course, there is nothing wrong with cotenants deciding among themselves that they will give each other a longer notice period. If a cotenant violates this internal agreement, the remaining tenants can go after him in small claims court for the time (expressed as rent money) they were shorted. But the remaining tenants will still have to pay the full rent to the landlord as long as the departing tenant gave the landlord the statutorily required notice.

If there’s a lease, the cotenant should either get permission from the landlord to leave early or, if this is impossible, find a new tenant acceptable to the landlord to take over. Again, if the cotenant has an under­standing with the remaining cotenants that no one will leave without giving a longer notice period to the others, she’ll have to deal with them if she splits early.

Unfortunately, cotenants often leave with not so much as a “goodbye,” let alone a substitute. Here are the options for the ones left behind.

What to Do If You Want to Stay

Let’s start with the worst-case scenario: Your cotenant leaves without the okay of the landlord. In this situation, the landlord has the option of evicting the rest of you, even if you can pay the full rent. How so? It goes back to joint and several liability: Moving out without the landlord’s permission is a violation of a lease clause, and one cotenant’s lease-breaking is a transgression for which all tenants are liable.

If you’re a troublesome group, your landlord may see this as a golden opportunity to be rid of you all. In practice, however, your landlord will probably let you stay if you’re decent tenants and you can pay the rent. If you're short on cash, you might ask the landlord to use the departed tenant’s share of the security deposit to help pay the rent until you find an acceptable replacement.

What to Do If You Want to Move Out, Too

If your cotenant skips out, leaving you in the lurch, you may decide that you don’t want to stay, either. To protect your security deposit and your good name at the credit bureau, follow these steps:

If you are a month-to-month tenant, give the required amount of written notice (usually 30 days) immediately. Don’t wait until you can’t pay the next month’s rent and receive a termination notice.

If you have a lease, let the landlord know in writing that you plan to move because you cannot afford the rent without your cotenant. Before you move, be extra accommodating when it comes to showing the unit to prospective renters. Facilitating a quick rerental is not just a courtesy to your landlord, but benefits you as well, since the sooner a new tenant takes over, the sooner your liability for the balance of the rent due under the lease ends. In addition, do your best to find an acceptable replacement tenant yourself.